9.1. Latency Benchmarks¶

Latency measurements are provided on the following environment:

Xeon – End-to-end latency measured with the RTI Connext DDS Performance Test tool on high-performance Xeon machines in a dedicated network .

9.1.1. Xeon¶

The end-to-end latency is measured between two identical machines, using the test configuration below and running the RTI Connext DDS Performance Test tool.

The test environment consists of the following:

x86_64 CentOS Linux release 7.1.1503
RTI Perftest 3.0
Switch Configuration: D-Link DXS-3350 SR:
- 176Gbps Switching Capacity
- Dual 10-Gig stacking ports and optional 10-Gig uplinks
- Stacks up to 8 units per stack
- 4MB (Packet Buffer Size)
- 48 x 10/100/1000BASE-T ports
Machine:
- Intel I350 Gigabit NIC
- Intel Core i7 CPU:
  - 12MB cache
  - 6 Cores (12 threads)
  - 3.33 GHz CPU speed
- 12GB memory

The latency is measured by sending one PING sample and wait for the Echoer to return the PONG sample. The sender records the time it took to receive the PONG sample and divides the result by 2. The test is repeated a number of times for each size. Note that the end-to-end latency is measured.

The following measurements are reported in the tables below:

Bytes - The size of the DDS sample payload in bytes (UDP overhead is not included).
Ave - Average latency
Std - Standard deviation
Min - The minimum latency
Max - The maximum latency
50% - The 50th percentile latency
90% - The 90th percentile latency
99% - The 99th percentile latency
99.99% - The 99.99th percentile latency

All values are reported in micro-seconds (µs).

9.1.1.1. C++ Best Effort keyed 1 Gbps¶

Table 9.1 C++ Best Effort keyed 1 Gbps¶
Bytes	Ave (µs)	Std (µs)	Min (µs)	Max (µs)	50% (µs)	90% (µs)	99% (µs)	99.99% (µs)
32	25	0.4	24	80	25	25	27	28
64	25	0.4	24	40	25	26	27	29
128	27	0.4	26	41	27	27	28	30
256	30	0.6	29	40	30	30	31	33
1024	44	0.5	43	56	44	44	45	48
4096	76	0.6	75	345	76	77	78	80
8192	113	0.6	112	231	113	114	115	119
63000	605	0.9	603	622	605	606	607	621

9.1.1.2. C++ Best Effort Unkeyed 1 Gbps¶

Table 9.2 C++ Best Effort Unkeyed 1 Gbps¶
Bytes	Ave (µs)	Std (µs)	Min (µs)	Max (µs)	50% (µs)	90% (µs)	99% (µs)	99.99% (µs)
32	24	0.3	23	35	24	24	26	27
64	24	0.5	23	39	24	25	26	28
128	26	0.3	25	46	26	26	27	29
256	29	0.5	28	334	29	29	30	32
1024	43	0.4	42	54	43	44	45	47
4096	76	0.5	75	169	76	76	78	80
8192	113	0.7	112	272	113	114	115	118
63000	605	0.9	603	622	605	606	608	619
32	24	0.6	24	43	24	25	26	28
64	25	0.6	24	271	25	25	26	29
128	26	0.4	25	267	26	26	28	30
256	28	0.6	28	291	28	29	30	33
1024	43	0.6	42	336	43	44	45	48
4096	76	0.6	75	287	76	76	78	80
8192	113	0.9	112	370	113	114	115	118
63000	605	1.2	603	775	605	606	607	622

9.1.1.3. C++ Reliable Keyed 1 Gbps¶

Table 9.3 C++ Reliable Keyed 1 Gbps¶
Bytes	Ave (µs)	Std (µs)	Min (µs)	Max (µs)	50% (µs)	90% (µs)	99% (µs)	99.99% (µs)
32	28	1.4	26	45	27	31	32	34
64	28	1.4	26	325	27	31	32	34
128	30	1.3	28	39	29	32	33	36
256	33	1.2	31	47	33	36	37	39
1024	47	1.2	46	335	47	49	50	53
4096	80	1.4	77	347	80	83	84	87
8192	117	1.4	114	390	117	119	121	124
63000	609	1.5	606	785	608	610	612	622
32	28	1.2	25	91	27	30	31	35
64	28	1.6	25	311	27	31	32	35
128	30	1.4	28	55	29	32	33	36
256	33	1.2	31	336	33	35	36	40
1024	48	1.2	46	514	47	50	50	53
4096	80	0.9	78	342	79	80	82	86
8192	117	1.5	114	381	117	119	120	124
63000	609	1.1	606	628	609	610	612	624

9.1.1.4. C++ Reliable Unkeyed 1 Gbps¶

Table 9.4 C++ Reliable Unkeyed 1 Gbps¶
Bytes	Ave (µs)	Std (µs)	Min (µs)	Max (µs)	50% (µs)	90% (µs)	99% (µs)	99.99% (µs)
32	27	1.9	25	312	27	30	34	36
64	28	1.3	26	51	28	30	31	35
128	29	1.4	27	42	29	32	32	37
256	32	1.1	30	64	32	34	35	38
1024	48	0.9	45	63	47	49	50	53
4096	80	1.2	77	298	79	82	83	86
8192	117	1.3	115	211	116	119	121	125
63000	609	1.5	607	807	609	611	613	624
32	27	1.3	24	312	27	30	31	34
64	28	1.6	25	322	27	31	32	37
128	28	1.4	26	307	28	31	32	36
256	33	1.3	30	632	32	35	35	38
1024	47	1.1	45	337	46	49	50	52
4096	80	1.4	78	550	79	82	83	85
8192	117	1.2	115	362	116	119	120	123
63000	609	1.7	607	898	609	610	612	628